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Panda Core is the core module of Panda Framework, it contains commonly used utility classes similar to apache-commons.
package panda.io.stream;
import java.io.Closeable;
import java.io.Flushable;
import java.io.IOException;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import panda.lang.Arrays;
import panda.lang.Chars;
import panda.lang.Collections;
import panda.lang.Strings;
/**
* CSV writer
*/
public class CsvWriter implements ListWriter, Closeable, Flushable {
private Appendable writer;
private char separator;
private char quotechar;
private char escapechar;
private String lineEnd;
private boolean forceQuote;
/**
* Constructs CSVWriter using a comma for the separator.
*
* @param writer the writer to an underlying CSV source.
*/
public CsvWriter(Appendable writer) {
this(writer, Chars.COMMA);
}
/**
* Constructs CSVWriter with supplied separator.
*
* @param writer the writer to an underlying CSV source.
* @param separator the delimiter to use for separating entries.
*/
public CsvWriter(Appendable writer, char separator) {
this(writer, separator, Chars.DOUBLE_QUOTE);
}
/**
* Constructs CSVWriter with supplied separator and quote char.
*
* @param writer the writer to an underlying CSV source.
* @param separator the delimiter to use for separating entries
* @param quotechar the character to use for quoted elements
*/
public CsvWriter(Appendable writer, char separator, char quotechar) {
this(writer, separator, quotechar, quotechar);
}
/**
* Constructs CSVWriter with supplied separator and quote char.
*
* @param writer the writer to an underlying CSV source.
* @param separator the delimiter to use for separating entries
* @param quotechar the character to use for quoted elements
* @param escapechar the character to use for escaping quotechars or escapechars
*/
public CsvWriter(Appendable writer, char separator, char quotechar, char escapechar) {
this(writer, separator, quotechar, escapechar, Strings.CRLF);
}
/**
* Constructs CSVWriter with supplied separator and quote char.
*
* @param writer the writer to an underlying CSV source.
* @param separator the delimiter to use for separating entries
* @param quotechar the character to use for quoted elements
* @param lineEnd the line feed terminator to use
*/
public CsvWriter(Appendable writer, char separator, char quotechar, String lineEnd) {
this(writer, separator, quotechar, quotechar, lineEnd);
}
/**
* Constructs CSVWriter with supplied separator, quote char, escape char and line ending.
*
* @param writer the writer to an underlying CSV source.
* @param separator the delimiter to use for separating entries
* @param quotechar the character to use for quoted elements
* @param escapechar the character to use for escaping quotechars or escapechars
* @param lineEnd the line feed terminator to use
*/
public CsvWriter(Appendable writer, char separator, char quotechar, char escapechar, String lineEnd) {
this.writer = writer;
this.separator = separator;
this.quotechar = quotechar;
this.escapechar = escapechar;
this.lineEnd = lineEnd;
}
/**
* Writes the entire list to a CSV file. The list is assumed to be a String[]
*
* @param allLines a List of String[], with each String[] representing a line of the file.
* @throws IOException if an IO error occurred
*/
public void writeAll(List allLines) throws IOException {
for (Iterator iter = allLines.iterator(); iter.hasNext();) {
Object nextLine = iter.next();
if (nextLine == null){
writeList(Collections.EMPTY_LIST);
}
else if (nextLine instanceof Collection) {
writeList((Collection)nextLine);
}
else if (nextLine instanceof Object[]) {
writeArray((Object[])nextLine);
}
else {
throw new IllegalArgumentException("the element of list is not a instance of Collection or String[].");
}
}
}
/**
* Writes the next element to the string buffer.
*
* @param sb string buffer to write to
* @param str a string to be write to string buffer
* @throws IOException
*/
private void writeItem(String str) throws IOException {
if (forceQuote) {
writer.append(quotechar);
for (int i = 0; i < str.length(); i++) {
char c = str.charAt(i);
if (c == quotechar || c == escapechar) {
writer.append(escapechar).append(c);
}
else {
writer.append(c);
}
}
writer.append(quotechar);
}
else {
boolean quoted = false;
for (int i = 0; i < str.length(); i++) {
char c = str.charAt(i);
if (c == quotechar || c == escapechar) {
if (!quoted) {
quoted = true;
writer.append(quotechar);
writer.append(str, 0, i);
}
writer.append(escapechar).append(c);
}
else if (c == Chars.CR || c == Chars.LF || c == separator) {
if (!quoted) {
quoted = true;
writer.append(quotechar);
writer.append(str, 0, i);
}
writer.append(c);
}
else {
if (quoted) {
writer.append(c);
}
}
}
if (quoted) {
writer.append(quotechar);
}
else {
writer.append(str);
}
}
}
/**
* Writes the list to the file.
*
* @param list a collection with each comma-separated element as a separate entry.
*/
@Override
public void writeList(Collection list) throws IOException {
int i = 0;
for (Iterator it = list.iterator(); it.hasNext();) {
if (i != 0) {
writer.append(separator);
}
Object e = it.next();
writeItem(e == null ? "" : e.toString());
i++;
}
writer.append(lineEnd);
}
/**
* Writes the next line to the file.
*
* @param array a string array with each comma-separated element as a separate entry.
* @throws IOException if an IO error occurred
*/
public void writeArray(Object[] array) throws IOException {
writeList(Arrays.asList(array));
}
/**
* Flush underlying stream to writer.
*
* @throws IOException if bad things happen
*/
public void flush() throws IOException {
if (writer instanceof Flushable) {
((Flushable)writer).flush();
}
}
/**
* Close the underlying stream writer flushing any buffered content.
*
* @throws IOException if bad things happen
*
*/
public void close() throws IOException {
if (writer instanceof Closeable) {
((Closeable)writer).close();
}
}
/**
* @return the separator
*/
public char getSeparator() {
return separator;
}
/**
* @param separator the separator to set
*/
public void setSeparator(char separator) {
this.separator = separator;
}
/**
* @return the quotechar
*/
public char getQuotechar() {
return quotechar;
}
/**
* @param quotechar the quotechar to set
*/
public void setQuotechar(char quotechar) {
this.quotechar = quotechar;
}
/**
* @return the escapechar
*/
public char getEscapechar() {
return escapechar;
}
/**
* @param escapechar the escapechar to set
*/
public void setEscapechar(char escapechar) {
this.escapechar = escapechar;
}
/**
* @return the lineEnd
*/
public String getLineEnd() {
return lineEnd;
}
/**
* @param lineEnd the lineEnd to set
*/
public void setLineEnd(String lineEnd) {
this.lineEnd = lineEnd;
}
/**
* @return the forceQuote
*/
public boolean isForceQuote() {
return forceQuote;
}
/**
* @param forceQuote the forceQuote to set
*/
public void setForceQuote(boolean forceQuote) {
this.forceQuote = forceQuote;
}
}